fix: handle tags including numbers in prepare command (#165)

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: teppeis

sources/Engine.ts

@@ -136,7 +136,7 @@ export class Engine {
       throw new UsageError(`This package manager (${descriptor.name}) isn't supported by this corepack build`);
 
     let finalDescriptor = descriptor;
-    if (/^[a-z-]+$/.test(descriptor.range)) {
+    if (!semver.valid(descriptor.range) && !semver.validRange(descriptor.range)) {
       if (!allowTags)
         throw new UsageError(`Packages managers can't be referended via tags in this context`);
 

tests/_runCli.ts

@@ -1,7 +1,7 @@
 import {PortablePath, npath} from '@yarnpkg/fslib';
 import {spawn}               from 'child_process';
 
-export async function runCli(cwd: PortablePath, argv: Array<string>) {
+export async function runCli(cwd: PortablePath, argv: Array<string>): Promise<{exitCode: number | null, stdout: string, stderr: string}> {
   const out: Array<Buffer> = [];
   const err: Array<Buffer> = [];
 

tests/main.test.ts

@@ -208,6 +208,26 @@ it(`should allow updating the pinned version using the "prepare" command`, async
   });
 });
 
+it(`should allow to call "prepare" with a tag`, async () => {
+  await xfs.mktempPromise(async cwd => {
+    await expect(runCli(cwd, [`prepare`, `--activate`, `npm@latest-7`])).resolves.toMatchObject({
+      exitCode: 0,
+      stderr: ``,
+    });
+
+    await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {
+      // empty package.json file
+    });
+
+    const npmVersion = await runCli(cwd, [`npm`, `--version`]);
+    expect(npmVersion).toMatchObject({
+      stderr: ``,
+      exitCode: 0,
+    });
+    expect(npmVersion.stdout).toMatch(/^7\./);
+  });
+});
+
 it(`should allow to call "prepare" without arguments within a configured project`, async () => {
   await xfs.mktempPromise(async cwd => {
     await xfs.writeJsonPromise(ppath.join(cwd, `package.json` as Filename), {